Preparation, characterization and luminescent properties of red-emitting phosphor: LiLa2NbO6 doped with Mn4+ ions

Series of Mn4+-activated LiLa2NbO6 red emitting phosphors were prepared by the solid state method. The structural and luminescence properties are investigated on the basis of X-ray diffraction (XRD), emission and excitation spectra, and luminescence decay curves. The LiLa2NbO6:Mn4+ phosphors can be efficiently excited by near-UV to blue light and exhibit bright red emission at around 712 nm, which can be assigned to the 2Eg→4A2g transition of the 3 d3 electrons in [MnO6] octahedra. Temperature dependent emission spectra and decay curves from 10 to 480 K are analyzed to understand the luminescence mechanism of Mn4+ in LiLa2NbO6 lattice. Notably, such a novel red emitting phosphor shows special anti-thermal quenching behavior.